Manufacturing method for batttery covers

ABSTRACT

A manufacturing method for a battery cover, in which plural molds are used for forming a space corresponding to a shape of the cover, the tab terminals are disposed in the space, synthetic resin is filled in the space to embed the tab terminals, characterized by that plural pieces made of the same material as the filled synthetic resin are installed with distances left between them on both surfaces of embedded portions of the tab terminals, and the tab terminals are disposed in the space under this state.

This application is a Rule 62 continuation of application Ser. No.07/885,636, filed May 19, 1992, now abandoned, which is a Rule 60Division of application Ser. No. 07/808,311, filed Dec. 16, 1991, nowU.S. Pat. No. 5,208,117.

BACKGROUND ART

This invention relates to a battery having a filling part and a pair oftab terminals on a convex portion of an upper surface of a cover so asto enable a connecting operation by mounting a receptacle housing offaston terminal type, and further to a manufacturing method for thecover for use in the battery.

Generally, batteries for use in small motorcycles and domestic electricequipments are made into very compact sizes. A battery having a fillingpart and terminals on an upper surface of cover, as described inUnexamined Patent Publication No. 2-129849 for example, is well known asa battery of such type. In this battery, a terminal wall in parallelwith filling parts arranged in longitudinal direction is formed, andterminals are installed on a side surface of the terminal wall.

In the above structure, however, it was required to connect a coupler toeach terminal. It was difficult to position the coupler so thatconnection work of coupler was not easy.

On the other hand, a charge operation is generally carried out byholding a charge clip to a terminal of cover in the battery. It was hardto hold the charge clip, or the terminal has the possibility that it isdamaged by operation mistake.

Further, a method using plural molds as illustrated by FIG. 16 is wellknown as a method for manufacturing the cover by embedding a part of aterminal shown in FIG. 1B in the cover of battery. In this method, aterminal 9 is supported at its portions 90 and 92 by a longitudinallymovable mold B and a stationary mold D, and is disposed under this statein a space 70 formed by an upper mold A, the longitudinally movable moldB, a vertically movable mold C and the stationary mold D. Syntheticresin such as polypropylene etc. is filled in the space 70 from a resinfilling port 71 of the upper mold A.

In the above-mentioned method, however, a filling pressure of syntheticresin during molding becomes extremely large, as high as 700 to 1,400kg/cm². Consequently, a longitudinal portion 91 of the terminal 9deformed to become in contact with an upper part of the stationary moldD and to be exposed to a battery inside after completion of the cover,and it was nonconformity of occuring cost-up by other method in order toprevent the possibility that the exposed portion 91 contacts with anelectrolyte.

This invention is made in order to solve the above problem asencountered in prior arts. A first object of the invention is to providea battery enabling a simple positioning of the receptacle housing andallowing an easy connection work of the receptacle housing, whenconnecting the receptacle housing of the faston terminal type to a tabterminal installed on the cover.

A second object of the invention is to provide a battery enabling acharge operation by easily connecting a standard charge clip.

A third object of the invention is to provide a manufacturing method forbattery cover preventing the terminal from being exposed to become incontact with an electrolyte.

SUMMARY OF THE INVENTION

In order to accomplish the first object in the battery of thisinvention, a convex portion is formed on an upper surface of a coverwith a part left on it, a filling part extending in upward andlongitudinal directions and a pair of tab terminals one ends of whichproject from the convex portion are installed on the convex portion, theother ends of the pair of terminals are extended in the cover so as tobe connected to a pair of posts of a container, and projecting ends ofthe pair of tab terminals are located with the filling part positionedbetween them and are projected in the same side in a longitudinaldirection so that the projecting ends are positioned on the uppersurface of the cover.

In this battery, a receptacle housing is positioned by an end of thefilling part and is connected to the tab terminals under a state wherethe housing is mounted on a part of the upper surface of the cover.

In order to accomplish the second object in the battery of thisinvention, the concave portion is provided on the upper surface of thecover, a pair of tab terminals are installed on one side of the concaveportion, the receptacle housing of faston terminal type is mounted tothe one side, two concave portions are formed which open only on sidesurfaces of the convex portion extending downward from positionsslightly displaced from the upper surface of the convex portion, or openover areas ranging from the side surfaces of convex portion to the sidesurfaces of cover, and charge terminals are installed in the concaveportions adjacent to their upper surfaces.

In this battery, the charge clip is connected by inserting one side ofclipping parts into the concave portion so as to clip the chargeterminal together with an upper wall of the concave portion. Thisconnecting operation can be done easily for the following reasons [1] to[3]. [1] The charge terminal can be clipped easily together with theupper wall of concave portion because it is installed in the concaveportion adjacent to the upper surface. [2] The upper wall of concaveportion has a thickness providing an easy clipping operation of thecharge clip, because the concave portion is formed in such the way asopening from the position slightly displaced from the upper surface ofconvex portion. [3] The concave portion has a space of size into whichone side of the clipping parts of charge clip can be inserted easily,because convex portion is formed which opens only on the side surface ofthe convex portion extending downward from the position displaced fromthe upper surface of the convex portion, or opens over the area rangingfrom the side surface of convex portion to the side surface of cover.Further, no influence is exerted on the tab terminals of faston terminaltype to which the receptacle housing of faston terminal type is mountedeven if any mistake is made during charge operation, because the chargeoperation is carried out at the charge terminals.

In order to accomplish the third object in the manufacturing method forbattery cover of this invention, in the battery cover having the convexportion including the filling part on its upper surface and having apair of tab terminals projecting from the convex portion at their oneends; plural molds are used for forming a space corresponding to a shapeof the cover, the tab terminals are disposed in the space, syntheticresin is filled in the space to embed the tab terminals, plural piecesmade of the same material as the filled synthetic resin are installedwith distances left between them on both surfaces of embedded portionsof the tab terminals, and the tab terminals are disposed in the spaceunder this state.

In this manufacturing method, the synthetic resin piece is active toprevent the tab terminal from moving vertically in the space into whichit is embedded. For this reason, there is no chance for the embeddedportion to deform due to a pressure of filling the synthetic resin evenif the embedded portion is long. Accordingly, there is no chance for theembedded portion of tab terminal to be exposed from the cover. Further,since the material of piece of synthetic resin is the same as that ofthe filled synthetic resin, an external appearance becomes uniform.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an oblique view showing a part of upper part of a batteryaccording to a first embodiment of this invention.

FIG. 2 is a view viewed in a direction of arrow II of FIG. 1.

FIG. 3 is an oblique view showing a receptacle housing of fastonterminal type, for reference of this invention.

FIG. 4 is a plan view showing a battery of a second embodiment accordingto the invention.

FIG. 5 is an oblique view showing a battery of a third embodimentaccording to the invention.

FIG. 6 is a view viewed in a direction of arrow VI of FIG. 5.

FIG. 7 is a sectional view taken on a line VII--VII of FIG. 5.

FIG. 8 is an oblique partial view showing a battery according to afourth embodiment of this invention.

FIG. 9 is a plan view of a battery using a cover manufactured by amanufacturing method shown by a fifth embodiment according to theinvention.

FIG. 10 is a sectional view taken on a line X--X of FIG. 9.

FIG. 11 is a sectional view taken on a line XI--XI of FIG. 9.

FIG. 12 is an oblique view showing a tab terminal immediately beforeattached with synthetic resin pieces.

FIG. 13 is an oblique view showing a tab terminal attached withsynthetic resin pieces.

FIG. 14 is a sectional view showing a state during molding of resin.

FIG. 15 is an oblique view showing a terminal for use in a conventionalmanufacturing method for battery cover.

FIG. 16 is a sectional view showing a state during molding of resin inthe conventional manufacturing method for battery cover.

DETAILED DESCRIPTION OF THE INVENTION First Embodiment

FIG. 1 is the oblique view showing a part of upper part of the batteryfor accomplishing the first object of the present invention and FIG. 2is the view viewed in the direction of arrow II of FIG. 1. In the bothfigures, 1 denotes a container and 2 denotes a cover, both havingrectangular shapes in their cross sections. A convex portion 3 is formedon an upper surface of the cover 2 with a portion 3a left on it. On theconvex portion 3, there provided a filling part 6 extending upward andlongitudinal directions (lateral direction in the figure) at a center ofthe convex portion 3 and a pair of tab terminals 9 and 9a one ends ofwhich project from the convex portion 3. 90 and 90a denote projectingends of the tab terminals 9 and 9a. The projecting ends 90 and 90a arelocated with the filling part 6 positioned between them, and project toa side (right side in the figure) in the longitudinal direction so as tobe positioned above the portion 3a on the upper surface of the cover 2.In FIG. 1, the projecting end 90 is located at the other side and theprojecting end 90a is located at this side.

On the other hand, a pair of poles 8 and 8a are installed on a sidesurface (a surface at this side of FIG. 1) 1a side of the container 1.The poles 8 and 8a are located on both longitudinal ends, i.e. the pole8 is located on a side of the projecting ends 90 and 90a (right side inthe figure) and the pole 8a is located on the opposite side (left sidein the figure). As illustrated by FIG. 2, the tab terminal 9 extendsthrough an inside of the cover 2 in a straight line to a side oppositeto the projecting end 90 and around the filling part 6 and then in astraight line, i.e. extends into a large L-shaped form and finally to beconnected to the pole 8. The other tab terminal 9a extends through theinside of the cover 9 in a straight line toward the projecting end 90for a short length to be connected to the pole 8a. 5 and 5a denotestoppers, and 7 denotes a projection for breaking through a thin filmwhich seals a filling container.

A receptacle housing of faston terminal type as shown by FIG. 3 ismounted and connected to the tab terminals 9 and 9a. In FIG. 3, 11 and11a denote claws engaging with the stoppers 5 and 5a, 12 and 12a denoteterminal holes in which the tab terminals 9 and 9a are inserted, 13 and13a denote connecting wires, and 14 denotes a recession fitting into anend of the filling part 6.

In the battery thus constructed, a connecting operation of thereceptacle housing to the tab terminals 9 and 9a is carried out under astate where the receptacle housing is positioned by the end of thefilling part 6 and placed on the portion 3a of upper surface of thecover 2. Accordingly, the connecting operation of the receptacle housingbecomes easy. The projecting ends 90 and 90a of the tab terminals 9 and9a are located with the filling part 6 positioned between them, andproject to the side (right side in the figure) in the longitudinaldirection so as to be positioned above the portion 3a on the uppersurface of the cover 2; so that there is no possibility of a decrease inarea of the filling part 6.

According to the present invention as described above, the convexportion 3 is formed on the upper surface of the cover 2 with the portion3a left on it, and the filling parts 6 extending upward and longitudinaldirections and a pair of tab terminals 9 and 9a, one ends 90 and 90a ofwhich project from the convex portion 3, are provided on the convexportion 3. The other ends of a pair of the tab terminals 9 and 9a areextended through the inside of the cover 2 so as to be connected to apair of the poles 8 and 8a of the container 1. The projecting ends 90and 90a of a pair of the tab terminals 9 and 9a are located with thefilling part 6 positioned between them and project to a side in thelongitudinal direction so as to be positioned above the upper surface ofthe cover 2. Consequently, the connecting operation of the receptaclehousing to the tab terminals 9 and 9a can be carried out under the statewhere the receptacle housing is positioned by the end of the fillingpart 6 and placed on the portion 3a of upper surface of the cover 2. Forthis reason, the connecting operation of the receptacle housing becomeseasy. The projecting ends 90 and 90a of the tab terminals 9 and 9a arelocated with the filling part 6 positioned between them, and project tothe side (right side in the figure) in the longitudinal direction so asto be positioned above the portion 3a on the upper surface of the cover2; so that the decrease in area of the filling part 6 can be avoided.

Second Embodiment

FIG. 4 is the plan view showing an alternate battery the firstembodiment according to the invention and is a view corresponding toFIG. 2. In FIG. 4, components attached with the same symbols as FIG. 2represent the same or corresponding components. The structure of thecover 2 including the convex portion 3, the stoppers 5 and 5a, and thefilling part 6, is similar to that of the first embodiment. Further, thestructure of the container 1 including the poles 8 and 8a is alsosimilar to that of the first embodiment.

In the present embodiment, tab terminals 4 and 4a are installed in thefollowing manner. The tab terminal 4 corresponding to the tab terminal 9of the first embodiment extends through the inside of the cover 2 in astraight line toward a projecting end 40 and around the filling part 6and then in a straight line, i.e. extends into a small L-shaped form andfinally to be connected to the pole 8a. The tab terminal 4acorresponding to the tab terminal 9a extends through the inside of thecover 2 in a straight line to a side opposite to the projecting end 40ato be connected to the pole 8.

In the battery thus constructed, the same effect as the first embodimentis also obtainable. That is, the connecting operation of the receptaclehousing (FIG. 3) becomes easy and there is no possibility of thedecrease in area of the filling part 6.

According to the structures of the tab terminals 4 and 4a of thisembodiment, a length of the tab terminal 4 becomes extremely shorterthan that of the tab terminal 9. Namely, a length of a portion 41extending through the inside of the cover 2 becomes extremely shorterthan that of a portion 91 (FIG. 2) of the tab terminal 9. Therefore,even if a short-circuit is produced between the tab terminals 4 and 4a,a temperature of the portion 41 of the tab terminal 4 will not become ashigh as that of the portion 91 of the tab terminal 9, and the cover 2will not be molten or burnt. 41a denotes a portion of the tab terminal4a extending through the inside of the cover 2.

The tab terminal 4a is formed into a straight shape, and the tabterminal 4 is formed into a small L-shape. Therefore, even when they aremade of a copper plate etc. by punching, a loss of material will besmall and a small press machine will do as compared with the case ofFIG. 2. Accordingly, the faston terminal can be manufactured at a lowcost.

Third Embodiment

In order to minimize sizes of the batteries having the structuresdescribed in the first and second embodiments as far as possible, it canbe considered that a height H (FIG. 1) of the convex portion 3 isreduced to mount a thin receptacle housing. However, it is supposed tobe hard to carry out the charge operation by clipping the projectingends 90 and 90a of the tab terminals 9 and 9a with the charge clip ifthe height H of the convex portion 3 is low. Because the upper surface3a of the cover 2 and the filling part 6 are located adjacent to theprojecting ends 90 and 90a. In case when the charge operation is carriedout by connecting a charger to the tab terminals 9 and 9a, there is apossibility that the receptacle housing could not be mounted due todamages of the tab terminals 9 and 9a if a short-circuit is producedbetween the tab terminals 9 and 9a caused by some operation mistake etc.The present invention is made in due consideration of the above point.

FIG. 5 is an oblique view showing the battery for accomplishing thesecond object of the present invention, and FIG. 6 is the view viewed inthe direction of arrow VI of FIG. 5. In the both figures, componentsattached with the same symbols as FIG. 1 represent the same orcorresponding components. In the battery of this embodiment, the heightH of the convex portion 3 is smaller than that of FIG. 1. A positivecharge terminal 20 and a negative charge terminal 50 (FIG. 6) areinstalled in the battery of this embodiment.

The convex portion 3 is so constructed that its three side surfaces 30a,30b and 30c are made flash with side surfaces 2a, 2b and 2c of the cover2. 30d denotes a side surface to which the receptacle housing of fastonterminal type as shown by FIG. 3 is mounted. A concave portion 21concaved into a rectangular parallelepiped is formed on a surfacecomposed of the side surface 30a and the side surface 2a. The positivecharge terminal 20 is installed in the concave portion 21. The chargeterminal 20 is installed adjacent to an upper face 21a among insidefaces of the concave portion 21 as illustrated by FIG. 7 which is thesectional view taken on a line VII--VII of FIG. 5. In this case, thecharge terminal 20 does not project from the concave portion 21. Theconcave portion 21 extends downward and opens from a position slightlydisplaced by a distance (h of FIG. 5) from the upper face 31 of theconvex portion 3, and its opening ranges from the side surface.30a tothe side surface 2a.

On the other hand, the negative charge terminal 50 is installed in thesame way as the positive charge terminal 20, in a concave portion 51formed on the surface composed of the side surface 30c and the sidesurface 2c in the same manner as the concave portion 21.

In order to charge the battery thus constructed, it is enough to connectthe positive and negative charge clips to the charge terminal 20 in theconcave portion 21 and the charge terminal 50 in the concave portion 51as shown by FIG. 7. Namely, in case of the concave portion 21, it isenough to put one side 41a of a clip 41 of the charge clip 40 in theconcave portion 21 and to locate the other side 41b above the concaveportion 21, so as to clip the charge terminal 20 together with the upperwall 22 of the concave portion 21. The same procedure may applied to thecharge terminal 50.

Such connection procedure of the charge clip 40 can be done easily forthe following reasons [1] to [3]. [1] Since the charge terminal 20 isinstalled adjacent to the upper face 21a in the concave portion 21, itcan be easily clipped together with the upper wall 22. [2] Since theconcave portion 21 extends downward and opens from the position slightlydisplaced by a distance (h of FIG. 5) from the upper face 31 of theconvex portion 3, the upper wall 22 of the concave portion 21 is formedinto a thickness h which can be clipped easily by the charge clip 40.[3] Since the concave portion 21 extends downward from the positionslightly displaced by a distance (h of FIG. 5) from the upper face 31 ofthe convex portion 3 and its opening ranges from the side surface 30a tothe side surface 2a, the concave portion 21 has a space large enough toincorporate the one side 41a of the clip 41 of the charge clip 40.

The above-mentioned matters are also applied to the connection of thecharge clip to the charge terminal 50.

Since the charge operation is carried out at the charge terminals 20 and50, the tab terminals 9 and 9a are not affected at all even if anymistake is made during the charge operation. Accordingly, it is possibleto carry out the connection by mounting the receptacle housing even ifany mistake is made during the charge operation.

The concave portion 21 and the concave portion 51 may be formed on anyside surface of the convex portion 3 other than the side surface 30d onwhich the receptacle housing is mounted, or it may be formed on the sameside surface.

The size of the concave portions 21 and 51 is not always necessary to beso large as ranging to the side surface of the cover 2, if it isprovided with a space large enough to incorporate the one side 41a ofthe clip 41 of the charge clip 40.

According to the present invention as described above, the concaveportions 21 and 51 are formed on the side surface other than the sidesurface 30d of the convex portion 3 to which the receptacle housing offaston terminal type is mounted, the concave portions 21 and 51extending downward from the position slightly displaced by the distance(h of FIG. 5) from the upper face 31 of the convex portion 3 and openingonly at the side surface of the convex portion 3 or ranging from theside surface of the convex portion 3 to the side surface of the cover 2,and the charge terminals 20 and 50 are installed in the concave portions21 and 51 adjacent to the upper faces of the concave portions 21 and 51.Therefore, the charge operation can be carried out easily by connectingthe standard charge clip 40, and the connecting operation can be done bymounting the receptacle housing even if any mistake is made during thecharge operation.

Fourth Embodiment

This is an alternate of the third embodiment. Namely, the concaveportion 21 and 51 may be formed into a shape as illustrated by FIG. 8.In the example of FIG. 8, the concave portion 21 is formed in thevicinity of the tab terminal 9a and opens also to the tab terminal 9aside. That is, the concave portion 21 has an opening 23a on a surfacecomposed of the side surface 30a and the side surface 2a, and has anopening 23b on the tab terminal 9a side. The opening 23b extends to theinnermost of the concave portion 21. The same is applied to the concaveportion 51.

In this structure, the one side 41a of the clip 41 of the charge clip 40can be slidden on the upper surface 3a of the cover 2 to be put easilyin the concave portion 21 from the opening 23b. Accordingly, the chargeclip 40 can be connected to the charge terminal 20 more easily ascompared with the third embodiment.

Fifth Embodiment

FIG. 9 is the plan view of the battery using the cover manufactured bythe manufacturing method for accomplishing the third object of thisinvention, FIG. 10 is the sectional view taken on the line X--X of FIG.9, and FIG. 11 is the sectional view taken on the line XI--XI of FIG. 9.In these figures, components attached with same symbols represent thesame or corresponding components. Namely, the convex portion 3 is formedon the upper surface of the cover 2 with the part 3a left on it. Thefilling part 6 extending upward and longitudinal directions and a pairof tab terminals 9 and 9a one ends of which project from the convexportion 3 are formed on the convex portion 3. The projecting ends 90 and90a of the pair of tab terminals 9 and 9a are located with the fillingpart 6 positioned between them, and are projected to the same side inthe longitudinal direction to be positioned on the upper surface 3a ofthe cover 2. The tab terminals 9 and 9a are embedded in the cover 2. Thetab terminal 9 is connected at its end 92 to the pole 8 of the container1, and the tab terminal 9a is connected at its end 92a to the pole 8a ofthe container 1, respectively. The receptacle housing of faston terminaltype as shown by FIG. 3 is mounted to the cover 2.

The cover 2 of such type is manufactured by the following methodincluding processes shown by FIG. 12 through FIG. 14. In FIG. 14,components attached with the same symbols as FIG. 16 represent the sameor corresponding components. In the first place, synthetic resin pieces101 and 102 as shown in FIG. 12 are to be prepared. Polypropylene etc.is to be used for synthetic resin. The synthetic resin pieces 101 and102 are plates bent into U-shaped form. In the second place, thesynthetic resin pieces 101 and 102 are fit to an embedded portion 91 ofthe tab terminal 9 with a distance left between them. This operation isto be carried out so as to clip the portion 91 of the tab terminal 9 bythe synthetic resin piece 101 and 102. In the third place, theprojecting end 90 of the tab terminal 9 is clipped by the longitudinallymovable mold B and mounted on the stationary mold D as illustrated inFIG. 14. Although not shown in the figure, the tab terminal 9a isclipped at its projecting end 90a by the longitudinally movable mold Band mounted at its end portion 92a on the stationary mold D. In thefourth place, upper and peripheral parts of the tab terminals 9 and 9aare surrounded by the upper mold A and the vertically movable mold C.Thus, a space 70 in which the tab terminals 9 and 9a are disposed isformed by the four molds A through D. The space 70 corresponds to ashape of the cover 2. In the fifth place, synthetic resin 72 having thesame material as the synthetic resin pieces 101 and 102 is filled in thespace 70 from a resin filling port 71 of the upper mold A. Then, themolds A through D are separated in a little while after completion ofsolidification of the synthetic resin 72.

In this manufacturing method, the synthetic resin pieces 101 and 102 areactive to prevent the portion 91 of the tab terminal 9 from displacingin a vertical direction within the space 72. For this reason, there isno possibility that the portion 91 is deformed by a pressure producedwhen filling the synthetic resin 72, even if the portion 91 is long.Therefore, there is no chance for the portion 91 of the tab terminal 9to be exposed from the cover 2. Further, since the synthetic resinpieces 101 and 102 have the same material as the synthetic resin 72, theappearance will become uniform.

The number of fit synthetic resin piece is not necessarily be two, butit may be three or more.

According to the manufacturing method of this embodiment as describedabove, the portion 91 of the tab terminal 9 can be embedded completelyin the cover 2 so as to prevent the tab terminal 9 from being exposed tobecome in contact with the electrolyte. Consequently, the tab terminal 9can be prevented from being corroded. Further, since the synthetic resinpieces 101 and 102 become uniform in their appearances with the filledsynthetic resin 72, the cover 2 looks well.

What is claimed is:
 1. A method of making a battery cover having aconvex portion including a filling part on its upper surface and havinga pair of tab terminals, one end of each tab terminal projecting fromthe convex portion, comprising:providing plural molds which form whenclosed a mold space corresponding to a desired shape of the cover,disposing plural U-shaped synthetic resin spacer around each tabterminal pieces spaced along each tab terminal, said U-shaped syntheticresin spacers each having a thickness which fills a portion in avertical direction of said mold space above and below each tab terminalwhen said molds are closed such that a distance is provided between topand bottom surfaces of each tab terminal and surfaces defining said moldspace; closing the molds; filling synthetic resin in the mold space toembed the tab terminals, said U-shaped synthetic resin spacer preventingdisplacement of the tab terminals during filling of the synthetic resin,said U-shaped spacers being made of the same synthetic resin as thesynthetic resin used for filling said mold space, thereby making saidbattery cover.